Have you resolved to get fit this year but don't know where to start? Maybe you're already in good shape, and want to know how to progress further. Or perhaps you're a fitness fanatic who needs advice on the finer points of your complex training regime …

Whatever your level of fitness, we're here to help. This weekend, we published a free two-part Guide to Getting Fit. In part one, Britain's medal-winning athletes tell you everything you need to know about running and swimming. In part two, they turn their attention to cycling, rowing and triathlon. Buy both booklets for £5 here, or find all the content online here.

If you're left with any unanswered questions, four of our fitness experts will be live online today from 1-2pm. Each of the experts compiled and wrote a section of the Getting Fit guides.

Sam Murphy will be tackling queries about running and triathlon. Sam is a fitness journalist and author, a qualified personal trainer, and has completed 14 marathons.

Direct your cycling questions to William Fotheringham. William has written about cycling for the Guardian and Observer since 1994, is the author of two bestselling books, and has been racing bikes for 25 years.

Peta Bee will be answering questions on swimming. Peta is an international athlete turned award-winning sports journalist.

Martin Cross will solve your rowing problems. Martin rowed for Great Britain for 20 years and competed in four Olympic games. He has coached up to international level and has reported for the Guardian at three Olympics.

Start posting your fitness questions now in the comments section below, and check back at 1pm in time for the live chat. If you have a question for a specific person, please precede it with that person's name. If you have a general query, or a question about a different sport, post it and one of the experts will endeavour to answer it.

And finally, don't wait for the experts! If you know the answer to someone's question, feel free to share your knowledge.